Truss topology optimization of timber-steel structures for reduced embodied carbon design

There is an increasing need for automated design processes that can help guide structural design towards lower embodied carbon solutions. This research presents a two-material truss topology optimization algorithm that aims at reducing the Global Warming Potential (GWP) of the designed structure. The ground structure approach is used and a new set of design variables are defined such that both the cross-sectional area and the material composition of each truss element is determined. The framework is developed for several different objective and constraint functions. These include designing for a minimum compliance objective with either weight or GWP constraints, and minimizing the GWP with stress constraints. The framework is demonstrated on truss designs with a mix of glue-laminated timber (GLT) and steel elements for both 2D and 3D design examples.